Using a box grater, shred the potato on the medium-sized grate. Transfer the shredded potato to a bowl of cold water. Let the shredded potato sit 1-2 minutes. While the potato is resting in the water, grate the onion. Add the onion to a medium sized mixing bowl.

Transfer the shredded potato onto a clean kitchen towel. Ring the potato out and remove as much liquid as possible; this will ensure a crispy perfectly cooked latke. Add the potato to the bowl.

To the onion and potato, add 1 beaten egg, ½ a teaspoon of salt and pepper, and 2 tablespoons of all purpose flour. Gently mix all of the ingredients together until just combined.

Fill a cast iron or heavy-bottomed skillet with ½-1-inch of oil. On medium high heat, heat the oil in the skillet. Once the oil is hot, free-form the potato mixture into patties and gently drop them into the skillet. Be careful not to overcrowd the pan, you will need to cook your latkes in batches. Cook the latkes until golden brown, about 3-4 minutes on each side. Keep an eye on the heat, you may have to raise and lower it periodically as the latkes cook; it’s too hot it will burn, and if it’s not hot enough the latkes won’t brown properly and they’ll get soggy. Transfer the cooked latkes to a paper-towel lined drying rack or plate.

for the sandwich

Thinly slice red onion.

Combine the creme fraiche and freshly chopped dill with a spoon in a small bowl.

Top a latke a slice of lox and thinly sliced red onion. Top the the lox with a dollop of the creme fraiche mixture. Place another latke on top of the creme fraiche and serve immediately.